The South African Navy demonstrated tangible progress in revitalising its mine countermeasures expertise during Exercise Phoenix 2025, a focused drill that integrated cutting-edge unmanned technology with traditional diving operations to counter underwater threats. Held in Saldanha Bay from February 10, 2025, the exercise marked a deliberate effort to revive capabilities that had been dormant for years, amid growing maritime risks from illicit mining, smuggling, and potential naval blockades in the Indian Ocean region. Commander Adam Williamson, who oversaw the event, described it to Navy News as a foundational step: the name Phoenix evoked themes of renewal forged through intense trials, mirroring the Navy’s push to rebuild from legacy shortfalls in doctrine, equipment, and personnel readiness.
Mine warfare remains a cornerstone of naval strategy for littoral nations like South Africa, where coastal waters host critical trade routes and offshore resources vulnerable to explosive hazards. The SAN’s historical emphasis on surface and subsurface patrols has waned since the post-apartheid era, leaving gaps in detecting and neutralising sea mines, which can disrupt shipping lanes or deny access to harbors with minimal enemy investment. Exercise Phoenix addressed this by prioritising the operational debut of the Navy’s newly acquired REMUS A100 autonomous underwater vehicle, a modular tool designed for shallow-water surveys that blend autonomy with human oversight. This platform, procured through Armscor’s 2023 tender for research and development, represents a shift toward unmanned systems that reduce risks to personnel while accelerating threat assessment in contested environments.
The exercise unfolded over two intensive weeks, drawing personnel from diverse units to foster cross-functional synergy. Starting with theoretical instruction at the Institute for Maritime Technology in Simon’s Town, participants covered mission planning, data analysis, and system integration under Project M/W SUPP 4, a sustainment initiative funded by the Director of Maritime Warfare. Six officers and eight ratings attended sessions on uploading navigation waypoints, demarcating operational zones, and processing sonar returns to generate dive targets. The REMUS A100, in its mine countermeasures variant, served as the centrepiece; operators learned to configure its sensors for autonomous runs, where the vehicle glides through predefined grids at depths up to 100 meters, mapping anomalies with side-scan sonar resolutions as fine as 5 centimetres per pixel. This data feeds into software that flags mine-like contacts, prompting follow-on dives by Operational Dive Division 1 teams equipped with rebreathers and neutralisers for visual confirmation or disposal.
Practical phases escalated the challenge, transitioning from controlled pool tests to open-water deployments in Saldanha’s variable currents and seabeds. Divers from the Maritime Reaction Squadron practised contact dives on simulated threats, verifying the AUV’s output against real-time visuals to refine classification algorithms. Williamson noted the inclusion of Naval Engineering Services for establishing an operational support baseline, which involved dissecting the vehicle’s 1.5-kilowatt-hour lithium-ion battery packs, three-bladed propulsors, and fault-tolerant electronics to craft maintenance protocols suited to South African dockyards. Operational Sea Training contributed evaluation metrics for deployment readiness, while SAS Simonsberg staff prototyped curricula for Mine Warfare Operator courses, blending classroom simulations with hands-on AUV handling to certify future specialists.
The REMUS A100’s technical profile underpins its value in these scenarios. Weighing under 40 kilograms when fully configured, this cylindrical vehicle—roughly 2 meters long and 19 centimetres in diameter—achieves speeds of 8 kilometres per hour with a 10-hour endurance, covering up to 70 kilometres per sortie on a single charge. Its modular nose houses interchangeable payloads: the 100M variant for mine hunting employs a high-frequency synthetic aperture sonar array operating at 1 megahertz, capable of imaging seafloor clutter in turbid waters where manned sweeps falter. Operators interface via a laptop-based console for waypoint scripting and real-time telemetry, with post-mission processing yielding geo-rectified mosaics that integrate with geographic information systems for threat prioritisation. Developed originally by Woods Hole Oceanographic Institution and now produced by Huntington Ingalls Industries following the 2020 acquisition of Hydroid, the REMUS series has proven itself in expeditionary roles worldwide, from port clearances to environmental mapping. For the SAN, the upgrade to the A100—enhanced with improved obstacle avoidance and reduced acoustic signatures—aligns with evolving doctrines that emphasize layered defences, where AUVs scout ahead of surface assets like the Valour-class frigates.
Beyond technical drills, Phoenix tested logistical chains essential for sustained operations. Road-transportable kits ensured the AUV could deploy from shore bases or the forthcoming multi-mission inshore patrol vessels, which will embark modular mine-hunting modules by 2027. The Mine Warfare Deployment Team concept emerged as a linchpin, comprising 20-25 sailors trained in AUV ops, diving, and data fusion to form plug-and-play units. This flexibility allows rapid response to incidents, such as clearing approaches to Durban or Cape Town harbours, without tying up larger warships. Challenges surfaced in supply coordination—minor delays in sensor calibration highlighted need for stockpiled spares—but these informed iterative standard operating procedures, validated through after-action reviews.
Williamson declared the exercise an unqualified triumph, affirming the SAN’s capacity for independent mine countermeasures and paving the way for formal A100 acceptance. With doctrines drafted, evaluation criteria set, and a maintenance regime in place, the Navy now possesses a blueprint for scaling up. Few refinements remain, primarily in streamlining transport from Simon’s Town to forward sites, but the trial of unmanned-diver workflows proved the concept viable, reducing exposure times in hazardous zones from hours to minutes.
Looking to the horizon, Exercise Phoenix positions the SAN to integrate mine warfare into joint exercises like IBSAMAR with India and Brazil, or African Maritime Security Symposium contributions. As budgets constrain major hull acquisitions, investments in unmanned assets like the REMUS offer cost-effective force multipliers, with lifecycle expenses under $500,000 per unit when amortised over a decade. This resurgence not only safeguards economic lifelines but also bolsters South Africa’s role in continental maritime governance, ensuring that rebirth from operational ashes yields a more resilient fleet.